Knock sensor for Lada Granta car 8 valves

Detonation has a negative effect on the Lada Granta engine. It has a destructive effect on the cylinder-piston group and other components. The electronic control module is capable of eliminating detonation.

To do this, he needs to receive information about the operating mode of the motor. The responsibility to monitor the occurrence of detonation is assigned to a special sensor. It promptly detects abnormal ignition of the fuel-air mixture and reports this to the ECU. As a result, engine operation is corrected and detonation goes away.

Purpose of the knock sensor

The knock sensor of Grant's car has the shape of a round torus with a hole for mounting in the center. There is a terminal block on its side that provides an electrical connection between the meter and the main power plant control module. A sensitive piezoelectric element is located inside the sensor. Engine operation and detonation are accompanied by vibrations, which are converted in the sensor into pulses of a certain amplitude and frequency.

Through wires, a voltage of a certain frequency and amplitude is supplied to the ECU. The main module analyzes the received data. A signal deviation from the norm indicates the appearance of detonation during engine operation. The electronic module sends control commands according to the established algorithms, and the ignition of the air-fuel mixture is normalized.

Eliminating detonation reduces parasitic loads on the engine. This has a good effect on its service life. Thus, the main purpose of the DD is to timely determine the occurrence of detonation and inform the main module about this, which ultimately results in an increase in the resource of the power unit.

Causes of detonation and measures to prevent it

Of course, the quality and type of gasoline used in the car is decisive. For example, the lower the octane number of the fuel, the less resistance to detonation. The quality of the fuel also plays an important role in the stable operation of the engine. Therefore, always pay attention to the choice of gas station, do not fill with low octane gasoline. The causes of the problems may also lie in faulty spark plugs, as a result of which the fuel in the cylinders does not ignite properly, and therefore signs of detonation appear.

Location of the knock sensor on the Lada Granta

For best sensitivity, the knock sensor on Lada Granta with an 8- and 16-valve engine is located directly on the cylinder block. It is screwed with a bolt into a pre-prepared threaded hole. The DD is located near the second cylinder. This is where the vibration during detonation is most pronounced.

Principle of operation

The device is built on the principle of the piezoelectric effect. The controller, perceiving the shock waves of the engine block, converts them into oscillations of electric current. When shock loads from fuel explosions occur in the internal element of the controller, the magnetic field changes, transforming the current characteristics. The amplitude of the electrical pulses is transmitted to the ECU, which in turn adjusts the fuel supply and changes the ignition timing. Repeated and prolonged explosion processes can lead to engine failure.

Design and operating diagram of the DD:

Sensor cost

On Lada Granta cars with power units with 16 and 8 valves, a proprietary knock sensor 21123855020 is installed. It is manufactured by Lada. The price of DD is 180-400 rubles. It is also possible to purchase an analogue. The table below presents the best alternative options for the original DD, which have worked well on Lada Granta cars.

Table - Good analogues of the original Lada Granta knock sensor

Replacement

• Disconnect the negative terminal of the battery

• Remove the connector from the sensor

• Unscrew the 13mm sensor with a wrench

• We dismantle the sensor and clean the DD seat with sandpaper

• Install the new one in reverse order.

We hope our article was useful to you.

Methods for checking a knock sensor

If you suspect a malfunction of the Lada Granta knock sensor, it is first recommended to check for errors generated by the on-board computer. From them you can understand that:

• the sensor produces a signal level that is too low;
• there is a break in the circuit between the meter and the ECU;
• The maximum permissible voltage at the DD output has been exceeded.

You can check the sensor without removing it from the Lada Grant. To do this, tap the sensitive part of the motor with a metal object while the engine is running. If the engine operation does not change, the sensor is faulty.

You can determine problems with the DD using a voltmeter or multimeter. To do this, it is recommended to use the instructions below.

• Remove the knock sensor from the Lada Granta.
• Connect both probes of a multimeter or voltmeter to the outputs of the DD terminal block.
• Using a metal rod, for example, a bolt, lightly tap on the working part of the meter.
• Look at the device. In the case of a working sensor, each blow should be accompanied by voltage surges.

Checking with a multimeter only indirectly confirms the serviceability of the knock sensor. This is due to the fact that for normal operation of the motor, the ECU must receive a signal of a certain frequency and amplitude. It is impossible to check this with a multimeter. Therefore, for a more accurate diagnosis of DD, it is recommended to use a special stand.

Diagnostics

At the first symptoms of detonation, you first need to pay attention to the quality of gasoline. It is almost impossible to fill the tank with counterfeit products at branded gas stations. Otherwise, you will have to drain all the gasoline. If this does not help, then there are signs of a controller malfunction. You can diagnose the device as follows:

• by turning the multimeter lever to voltmeter mode, set the measurement zone within 200 mV;
• the device clamps are installed on contacts “A” and “C” of the controller (see the top diagram);
• by tapping a metal object (screwdriver or pliers) on the sensor body, record the voltmeter readings;
• if the voltage increases, then the device is working properly and the cause of the explosive processes must be sought elsewhere;
• the absence of changes in the multimeter readings will mean that the meter has become unusable and requires replacement.

Self-replacement of the sensor on a Lada Granta

Instructions for replacing the knock sensor on a Lada Granta are presented below.

• Secure the vehicle by applying the parking brake.
• Open the hood.
• Disconnect the negative terminal of the battery, turning off the power to the on-board network. This action will protect you from the risk of electrical injury.

• Press the latch and disconnect the terminal block.

• Unscrew the sensor.

• Remove the knock sensor together with the bolt securing it.

• Install a new DD.

• Reassemble everything in the reverse order of removal.

What happens if you don’t change the DD?

If you neglect to replace the sensor, then detonation in the engine will begin to progress and cause irreversible damage to the engine and bring major repairs ahead of schedule. Also, the operation of the sensor directly affects engine power and its consumption; the cost of the sensor is not comparable to the costs of subsequent repairs or the costs of increased fuel consumption.

Determining the malfunction

There are two ways to determine a possible breakdown. The easiest way is to use the services of a car service. Experienced specialists, using certain devices, will quickly identify the presence and cause of a malfunction. The maximum diagnostic period is 1 hour. If you want to save money, you can check the condition of the DD yourself.

It is quite simple to independently determine the malfunction of the knock sensor. To do this, you do not need to have any deep knowledge, only your attentiveness. You should think about organizing diagnostics of the device when the knock sensor shows the following signs of malfunction:

• you notice a significant loss of power from the internal combustion engine;
• acceleration of your car has become “sluggish” and difficult;
• there is an unreasonable increase in fuel consumption;
• the exhaust became smoky;
• the presence of a detonation process;
• The “Check Engine” light on the control panel is on.

The self-check procedure looks like this:

• We remove protection in the garage. You have to work with the engine itself.
• We exclude a break in the shielding braid or signal wire.
• If the problem is not a break, then you need to focus on the outlet itself. It may need replacing.
• Checking DD contacts.
• We carry out diagnostics using a standard multimeter.

You can determine whether the device is faulty using a digital multimeter. Measure the resistance level of the DD contacts. Any deviation from the norm will be a reason to replace the device with a new one. Before you begin, you should find out the resistance standard for your car brand. As practice shows, this indicator can vary greatly for different brands of cars. To avoid wasting time and money, you need to arm yourself with the necessary information.

You can check the functionality of the sensor by measuring the voltage of the contacts. Carefully unscrew the sensor from the cylinder block. Apply voltage to one contact and connect ground to the negative drive. Hold the DD itself with your hand and hit it on any surface. If the device is working properly, then after contact between shocks a voltage of 30-40 millivolts should appear; if it is absent, then it requires replacement.

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The main symptoms of a malfunction of the knock sensor on the VAZ-2112 valve 16

The knock sensor on the 16-valve VAZ-2112 has the same malfunction conditions as some GAZ, Toyota, Gazelle, Priora and Kalina cars. Replace the knock sensor yourself. Detailed article about replacing the temperature sensor, which replaces the valves of the VAZ-2112 16. 2. Replacing the knock sensor. 16:23. New. Naturally, not every motorist will be able to discover that this is the same sensor, but you can see the direct and indirect causes of the malfunction.

The video provides an overview of the main malfunctions and diagnostics of the wideband knock sensor on the VAZ-2112:

Symptoms of knock sensor failure

Resistance that the sensor must have in good working order

Before looking at the causes, you need to look at the symptoms of the problem. So, let's look at what else can cause the bell to ring when the knock sensor fails:

• The engine is losing power.
• The acceleration potential drops.
• Increased fuel consumption.
• CHECK Dashboard light is on.
• Smoke exhaust.
• Presence of detonation.
• The engine began to flicker.

Of course, an important reason for failure is the knock sensor. this is the fuel mixture, namely the quality of the gasoline itself. The lower the octane number, the lower the resistance to detonation. phase sensor 2110, 2111, 2112 16cl. Where is the phase sensor located? Error p0340. Replacing the camshaft position sensor on a 16 valve engine. If the fuel explodes, it will not burn completely in the engine and you will hear the muffler burning.

Replacing the knock sensor

by car Lada priority

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Replacing the detonation sensor. Error P0325.

Happy everyday life of an AvtoVAZ owner: trip-repair, trip-repair. Replacing the knock sensor on the valves of a VAZ-2112 16: photo a. Symptoms of detonation of 16-valve VAZ-2112 valves. Change Knock Sensor

Knock sensor diagnostics

The sensor was checked with a multimeter. Replacing valves with the previous 16 valves. In this case, “knock out” the sensor using a screwdriver

To diagnose the knock sensor, it is removed from the engine and a voltmeter with a measurement limit of up to 200 mV is connected to it.

The sensor then “knocks” on a hard surface and looks at the voltmeter. When pressed, the reading should change. If they do not change, the sensor does not work. If they change, then the sensor readings change, but whether they are correct is in question!

ECU fault signal

If the sensor fails, a characteristic knocking sound will immediately be detected. Many motorists simply reset the "negative terminal" to reset the ECU to zero, but it is worth understanding the reasons for this effect and eliminating them. Replacing the timing belt. Previous 16 valves. Let's look at the ECU error codes that signal the output of the knock sensor:

code-0325 hints at problems with the network. Replacing the 16-phase phase sensor VAZ 2112 Replacing the timing belt: previous 16 valves. For example, a break in the wiring or acidification of the plug contacts. In this case, we call the electrical connection of the sensor, clean the electrical contacts;

Error 0325 on the BK STAT screen (knock sensor circuit open)

Knock sensor type

conclusions

It is quite simple to determine the failure of the VAZ-2112 16 valve. The first sign will be electronic errors in the engine control unit and a light in the Check Engine dashboard. Additionally, a simple multimeter test will tell you if the product has truly failed. If the sensor is faulty, it must be replaced.

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Preparatory actions

Before performing any operations on electrical equipment, you must disconnect the battery. It will be enough to loosen the screw holding the negative terminal on the battery, and then remove this terminal while working. Here you will need a 10mm spanner:

The negative terminal turns off faster

Let's say in your case we are talking about an 8-valve engine. Then you can go straight to the next chapter. Owners of cars with engines 21126/21127 are less fortunate - they need to dismantle the casing.

In order to remove the protective casing, the following steps are carried out: disconnect the canister valve cables, remove the iron retaining plate, then remove the valve module from the engine. Only then will it be possible to unscrew the plug covering the oil filler neck. The part itself, called the “casing,” is carefully pulled up. It is held in place by rubber rivets.

The part is held in place by four rubber rivets.

After dismantling the protection, it would be advisable to tighten the oil filler plug. Otherwise, dust will get into the neck. In general, care must be observed at every step.

Tips for choosing

In the catalog of assembly units compiled by AvtoVAZ, the knock sensor is designated as follows: 21120-3855020-01 or 02. Both options are suitable for all engines standard installed on Kalina-2. It is clear that the part with the designation “01” is produced by AvtoVAZ OJSC. Products from other factories are characterized by alternative designations: “02” and “03”.

You can check the performance of sensors based on the principle of the piezoelectric effect:

1. A voltmeter is connected to the sensor terminals;
2. Set the minimum value limit;
3. Tapping the housing with a screwdriver controls the voltage.

The ECU unit can store two types of errors: 0327, 0328. A low amplitude at the contacts is indicated by the appearance of the first of them (0327). The second is the opposite effect, when the amplitude at the sensor terminals exceeds the limits.

Are your fingers tapping?

Let's define what detonation is and what causes it.

Anyone who has ever heard of civil defense and protection from a nuclear explosion remembers that one of the effects of such an explosion is a shock wave. By the way, we also encounter a shock wave when flying a supersonic aircraft. In short, this is a wave propagating in a certain medium (in our case, air) at the speed of sound.

Now let's go on an excursion into the engine cylinder - at the moment when the working mixture ignites. If combustion proceeds in the usual manner, then the speed of propagation of the flame front and, accordingly, the increase in pressure is low (usually up to 50 m/s). But it happens that conditions are created for combustion at higher speeds.

So, if the flame front propagates at the speed of sound, then the shock wave, which has significant energy, is what causes the engine parts to emit those sounds that we call detonation knocks. In general, the shortest and most correct definition of detonation is “combustion in the front of a shock wave.”

Functionality check

In order to dispel all doubts regarding the serviceability of the product, it is necessary to dismantle it. The test is carried out using a multimeter, connecting it to the sensor terminals. The operating and measuring parameters of the device are set within the range of up to 200 mV. After that, the working side of the sensor is knocked on a metal surface and at the same time the readings of the multimeter are observed. If the readings do not change when tapping, we can say with 100 percent probability that the sensor is faulty.

There is another quite useful diagnostic method. It consists in checking the proper supply of the required voltage to the contact block, which is connected to the DD. To check the block, you need to disconnect it from the sensor and measure its contact group with a measuring device (the engine must be running when checking). First, the voltmeter must be switched to the alternating current measurement mode. If voltage is not supplied to the chip, then the cause of the viburnum knock sensor error may be due to a broken electrical wiring or oxidation.

The third method is to replace the “suspect” with a new, known-good device. In addition, it is necessary to understand that in some cases the operation of the system that detects detonation processes may be hampered by: - ​​broken electrical wiring or oxidized contacts at the junctions of elements, as a result - a low signal level of the Viburnum knock sensor; — poor tightening of the fastening nut.

Detonation. Arbitrary self-ignition of fuel

Detonation is formed in the combustion chamber during the chemical reaction of combustion of the gasoline mixture. During the chain reaction, gaseous secondary products, mixing with the vapors of the initial mixture, re-enter the combustion process, creating an uncontrolled explosion and spontaneous combustion of the fuel mixture. In essence, this is an unintended and untimely combustion, accompanied by a blast wave and increased coking.

So, starting the next stroke, the piston in the internal combustion engine compresses the mixture, creating pressure in the cylinder. Then, after some time (fractions of a second), ignition should occur. However, due to the above reasons, abnormal ignition occurs already at the moment of compression (without withstanding that split second). The flame spreads throughout the chamber and a front of increased pressure is formed. Coupled with the pressure of the piston on the mixture, the pressure from premature combustion creates conditions for the formation of volatile, flammable compounds (alcohols, formaldehydes, oxides), which trigger a chain reaction. The result of all this is a point self-ignition of an explosive nature.

Mass air flow sensor (MAF)

This important sensor is located behind the engine air filter. It is also called an air flow meter. Its purpose is to estimate the amount of air entering the car engine. Based on the information received from the sensor, the electronic control unit (ECU) calculates the required amount of fuel to maintain the stoichiometric fuel-to-air ratio for the given engine operating conditions.

See “How to check the mass air flow sensor on LADA cars”

The number of real reasons is three

We have not yet identified the reasons for the detonation of the injection engine. You can safely fill in any fuel, even with impurities, and you can completely disable the knock sensor - the engine will continue to run, but the ECU will adjust the ignition accordingly. Three factors lead to the appearance of stable detonation: operation on a lean mixture, glow ignition, overheating of the walls of the combustion chamber. The last of the factors is caused by only one reason - a breakdown of the temperature sensor (DTOZ).

DTOZh sensors for Lifan cars

Listed below are sensors, the serviceability of which is also important.

Sensor failure cheat sheet

The injection gasoline engine is equipped with a set of elements that allow you to control the operation of the system at any given time. All these elements are called sensors. We list those whose failure leads to detonation:

• TPS, or throttle position sensor. Symptoms of failure are a decrease in power, jerks and dips during acceleration, as well as unstable idling. The result is that the engine runs on a lean mixture, but only under heavy loads. And detonation will appear if the control is carried out in a “pedal to the floor” style. The check engine light usually does not come on.
• DTOZH, that is, the antifreeze temperature sensor. If the engine is heated to a critical temperature, the ECU must “know” about it. The ignition timing must then be adjusted. Otherwise, and quite quickly, a stable detonation will begin.
• DD, knock sensor. This element rarely fails, but the wiring may be damaged. If the sensor breaks down, and not if the wires are broken or shorted, the Check Engine lamp does not light up at low speeds. If there is already a malfunction, you can cause detonation like this: you need to turn off the engine, disconnect and reconnect the battery terminal, and start. Detonation will appear and then disappear until the next start.

The DTOZh sensor breaks down - we get detonation in critical modes. And if the TPS breaks down, detonation is observed at high speeds. The appearance and rapid disappearance of detonation is the result of a motor failure.

A motor failure can lead to detonation when the ignition is turned off.

A variable resistor senses the angle of rotation of the damper

Microphone, that is, a piezoelectric element that monitors detonation

Operating an engine with a faulty throttle sensor is not uncommon. Car owners give reasons: the warning light did not turn on, there are jerks and dips only during acceleration, and a metallic sound cannot always be noticed. It seems that it is necessary to change the gasoline, and not the sensor, but in fact it is the other way around.

What are the dangers of glow ignition?

Let’s say a spark plug heats up “white-hot” and doesn’t cool down even by the next compression stroke. Then ignition occurs before a spark appears. Pre-ignition, as we know, always causes detonation. Thus, it can also be caused by the “glow ignition” that was just described.

Foci of ignition are accumulations of soot

There can be several reasons for the occurrence of glow ignition:

• Accumulation of a large amount of soot and soot on candles;
• Burnout of the “central electrode”.

Actually, this is all that can be said about another factor associated with the occurrence of detonation. Let's consider the last of them - the problem with the injectors.

Clogged injectors and consequences

In fact, the rule always applies: if any injector becomes clogged (here is an article on how to clean it), engine power is reduced. This is how the ECU works to prevent detonation. The logic here is as follows: the injector becomes clogged, the mixture becomes lean, and detonation occurs. The sensor is triggered, and the ECU performs regulation, adjusting all parameters to the operating conditions. But such “adjustment” causes a decrease in power and cannot be carried out indefinitely.

Set of nozzles after ultrasonic cleaning

If the degree of clogging is sufficiently high, the ECU cannot correct the situation: the mixture is lean, and detonation occurs all the time. The Check Engine light may also come on, and the BC, if present, will display the following error - P0324.

Code P0324 is deciphered as follows: “detonation control error.” But the DD sensor and its circuits may turn out to be serviceable! Then, of course, you will need to check the injectors.

It turns out that with the Check Engine light on, especially when the errors are related to detonation, you cannot operate the engine. But on the other hand, neither a break nor a failure of the sensor itself leads to fatal consequences. The Check lamp, moreover, will light up in all cases. Well, it’s better to be able to recognize detonation by ear.

The main signs of detonation

They say that detonation is immediately recognized by a characteristic sound - a clattering sound, a ringing sound, a metallic knock. The sources of ignition are located away from the spark plug, and a blast wave is formed in the chamber volume at increased pressure. Outwardly, this manifests itself as if the walls of the cylinder are being hit with a hammer from the inside.

Dependence of pressure on phase, graph

In addition, the color of the exhaust changes when detonation occurs - it becomes dark black. The temperature of the exhaust gases also changes and decreases. But it will be difficult to notice these phenomena, and if detonation occurs for a short time, it will be practically impossible. Speaking about stable detonation, it should be noted that it can only be caused under load.

There is no point in opening the hood and trying to “accelerate” while monitoring the exhaust - most likely, the effect will not appear. There is also no point in listening to the engine - it needs additional load. Well, few people can hear the “knock of fingers” when driving at speed.

In practice, only indirect signs are often used - failures, overheating, etc. We list them in the chapter on reasons.